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Kuan MTY, Yadav K, Castaldo M, Tan J, Chan NH, Traynor M, Hosking M, Skarsgard E, Ting JY. The impact of a care bundle with an emphasis on hemodynamic assessment on the short-term outcomes in neonates with congenital diaphragmatic hernia. J Perinatol 2024; 44:348-353. [PMID: 37935830 DOI: 10.1038/s41372-023-01807-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 10/13/2023] [Accepted: 10/17/2023] [Indexed: 11/09/2023]
Abstract
OBJECTIVE To evaluate the short-term outcomes of implementing a care bundle emphasizing frequent hemodynamic assessments by echocardiography in neonates with congenital diaphragmatic hernia (CDH). STUDY DESIGN This was a retrospective cohort study of infants with CDH admitted to a quaternary perinatal unit from January 2013 to March 2021. The primary composite outcome was defined as mortality or use of extracorporeal membrane oxygenation or need for respiratory support at discharge. RESULTS We identified 37 and 20 CDH infants in Epoch I and II, respectively. More patch repairs (50% vs. 21.9%, p = 0.035) and echocardiograms (6[4-8] vs. 1[0-5], p = 0.003) were performed in Epoch II. While there were no differences in the primary outcome, there was a reduction in mortality in Epoch II (0% vs. 27%, p = 0.01). CONCLUSION With the implementation of a CDH care bundle with an emphasis on hemodynamic assessment, we demonstrated a significant reduction in mortality.
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Affiliation(s)
- Mimi T Y Kuan
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Krishan Yadav
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Michael Castaldo
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Jason Tan
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Natalie H Chan
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
- Department of Pediatric and Newborn Medicine, UCSF and Benioff Children's Hospital, San Francisco, CA, USA
| | - Michael Traynor
- Department of Anesthesiology, University of British Columbia, Vancouver, BC, Canada
| | - Martin Hosking
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Erik Skarsgard
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Joseph Y Ting
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada.
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada.
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2
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Chan NH, Gomez CA, Vennelakanti V, Du Q, Kulik HJ, Lewis JC. Non-Native Anionic Ligand Binding and Reactivity in Engineered Variants of the Fe(II)- and α-Ketoglutarate-Dependent Oxygenase, SadA. Inorg Chem 2022; 61:14477-14485. [PMID: 36044713 PMCID: PMC9789792 DOI: 10.1021/acs.inorgchem.2c02872] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Mononuclear non-heme Fe(II)- and α-ketoglutarate-dependent oxygenases (FeDOs) catalyze a site-selective C-H hydroxylation. Variants of these enzymes in which a conserved Asp/Glu residue in the Fe(II)-binding facial triad is replaced by Ala/Gly can, in some cases, bind various anionic ligands and catalyze non-native chlorination and bromination reactions. In this study, we explore the binding of different anions to an FeDO facial triad variant, SadX, and the effects of that binding on HO• vs X• rebound. We establish not only that chloride and bromide enable non-native halogenation reactions but also that all anions investigated, including azide, cyanate, formate, and fluoride, significantly accelerate and influence the site selectivity of SadX hydroxylation catalysis. Azide and cyanate also lead to the formation of products resulting from N3•, NCO•, and OCN• rebound. While fluoride rebound is not observed, the rate acceleration provided by this ligand leads us to calculate barriers for HO• and F• rebound from a putative Fe(III)(OH)(F) intermediate. These calculations suggest that the lack of fluorination is due to the relative barriers of the HO• and F• rebound transition states rather than an inaccessible barrier for F• rebound. Together, these results improve our understanding of the FeDO facial triad variant tolerance of different anionic ligands, their ability to promote rebound involving these ligands, and inherent rebound preferences relative to HO• that will aid efforts to develop non-native catalysis using these enzymes.
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Affiliation(s)
- Natalie H. Chan
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Christian A. Gomez
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Vyshnavi Vennelakanti
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Qian Du
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Heather J. Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Jared C. Lewis
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
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Yee CH, Wong HF, Tam MHM, Yuen SKK, Chan HC, Cheung MH, Yu ATO, Chiu Y, Chan NH, Leung LH, Ng ATL, Law DMC, Ng TL, Teoh JYC, Chiu PKF, Ng CF. Effect of SARS and COVID-19 outbreaks on urology practice and training. Hong Kong Med J 2021; 27:258-265. [PMID: 33632937 DOI: 10.12809/hkmj208822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION The objective was to investigate the changes in urology practice during coronavirus disease 2019 (COVID-19) pandemic with a perspective from our experience with severe acute respiratory syndrome (SARS) in 2003. METHODS Institutional data from all urology centres in the Hong Kong public sector during the COVID-19 pandemic (1 Feb 2020-31 Mar 2020) and a non-COVID-19 control period (1 Feb 2019-31 Mar 2019) were acquired. An online anonymous questionnaire was used to gauge the impact of COVID-19 on resident training. The clinical output of tertiary centres was compared with data from the SARS period. RESULTS The numbers of operating sessions, clinic attendance, cystoscopy sessions, prostate biopsy, and shockwave lithotripsy sessions were reduced by 40.5%, 28.5%, 49.6%, 44.8%, and 38.5%, respectively, across all the centres reviewed. The mean numbers of operating sessions before and during the COVID-19 pandemic were 85.1±30.3 and 50.6±25.7, respectively (P=0.005). All centres gave priority to cancer-related surgeries. Benign prostatic hyperplasia-related surgery (39.1%) and ureteric stone surgery (25.5%) were the most commonly delayed surgeries. The degree of reduction in urology services was less than that during SARS (47.2%, 55.3%, and 70.5% for operating sessions, cystoscopy, and biopsy, respectively). The mean numbers of operations performed by residents before and during the COVID-19 pandemic were 75.4±48.0 and 34.9±17.2, respectively (P=0.002). CONCLUSION A comprehensive review of urology practice during the COVID-19 pandemic revealed changes in every aspect of practice.
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Affiliation(s)
- C H Yee
- SH Ho Urology Centre, Department of Surgery, The Chinese University of Hong Kong, Hong Kong.,Department of Surgery, Prince of Wales Hospital, Shatin, Hong Kong
| | - H F Wong
- SH Ho Urology Centre, Department of Surgery, The Chinese University of Hong Kong, Hong Kong.,Department of Surgery, Prince of Wales Hospital, Shatin, Hong Kong
| | - M H M Tam
- SH Ho Urology Centre, Department of Surgery, The Chinese University of Hong Kong, Hong Kong.,Department of Surgery, Alice Ho Miu Ling Nethersole Hospital, Hong Kong
| | - S K K Yuen
- SH Ho Urology Centre, Department of Surgery, The Chinese University of Hong Kong, Hong Kong.,Department of Surgery, North District Hospital, Hong Kong
| | - H C Chan
- Department of Surgery, United Christian Hospital, Hong Kong
| | - M H Cheung
- Department of Surgery, Tseung Kwan O Hospital, Hong Kong
| | - A T O Yu
- Department of Surgery, Tuen Mun Hospital, Hong Kong.,Department of Surgery, Pok Oi Hospital, Hong Kong
| | - Y Chiu
- Department of Surgery, Princess Margaret Hospital, Hong Kong
| | - N H Chan
- Department of Surgery, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | - L H Leung
- Department of Surgery, Kwong Wah Hospital, Hong Kong
| | - A T L Ng
- Department of Surgery, Queen Mary Hospital, Hong Kong.,Department of Surgery, Tung Wah Hospital, Hong Kong
| | - D M C Law
- Department of Surgery, Caritas Medical Centre, Hong Kong
| | - T L Ng
- Department of Surgery, Queen Elizabeth Hospital, Hong Kong
| | - J Y C Teoh
- SH Ho Urology Centre, Department of Surgery, The Chinese University of Hong Kong, Hong Kong.,Department of Surgery, Prince of Wales Hospital, Shatin, Hong Kong
| | - P K F Chiu
- SH Ho Urology Centre, Department of Surgery, The Chinese University of Hong Kong, Hong Kong.,Department of Surgery, Prince of Wales Hospital, Shatin, Hong Kong
| | - C F Ng
- SH Ho Urology Centre, Department of Surgery, The Chinese University of Hong Kong, Hong Kong.,Department of Surgery, Prince of Wales Hospital, Shatin, Hong Kong
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4
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Chan NH, Lee SY, Cheng NHY, Wong HY, Lo WK, Lung DC. Hospital infection control best practice: Five essential elements to successfully minimize healthcare-associated COVID-19. Infect Prev Pract 2020; 3:100110. [PMID: 34316572 PMCID: PMC7837126 DOI: 10.1016/j.infpip.2020.100110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 12/10/2020] [Indexed: 01/22/2023] Open
Affiliation(s)
- N H Chan
- Infection Control Team, Queen Elizabeth Hospital, Hong Kong Special Administrative Region
| | - S Y Lee
- Infection Control Team, Queen Elizabeth Hospital, Hong Kong Special Administrative Region
| | - N H Y Cheng
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong Special Administrative Region
| | - H Y Wong
- Infection Control Team, Queen Elizabeth Hospital, Hong Kong Special Administrative Region
| | - W K Lo
- Infection Control Team, Queen Elizabeth Hospital, Hong Kong Special Administrative Region
| | - D C Lung
- Infection Control Team, Queen Elizabeth Hospital, Hong Kong Special Administrative Region.,Department of Pathology, Queen Elizabeth Hospital, Hong Kong Special Administrative Region
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5
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Chan NH, Gair JJ, Roy M, Qiu Y, Wang DS, Durak LJ, Chen L, Filatov AS, Lewis JC. Insight into the Scope and Mechanism for Transmetalation of Hydrocarbyl Ligands on Complexes Relevant to C–H Activation. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00628] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Natalie H. Chan
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Joseph J. Gair
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Michael Roy
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Yehao Qiu
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Duo-Sheng Wang
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Landon J. Durak
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Liwei Chen
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Alexander S. Filatov
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Jared C. Lewis
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
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6
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Gair JJ, Qiu Y, Khade RL, Chan NH, Filatov AS, Zhang Y, Lewis JC. Synthesis, Characterization, and Theoretical Investigation of a Transition State Analogue for Proton Transfer during C–H Activation by a Rhodium-Pincer Complex. Organometallics 2019. [DOI: 10.1021/acs.organomet.8b00887] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Joseph J. Gair
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Yehao Qiu
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Rahul L. Khade
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Natalie H. Chan
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Alexander S. Filatov
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Yong Zhang
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Jared C. Lewis
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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7
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Gair JJ, Qiu Y, Chan NH, Filatov AS, Lewis JC. Rhodium Complexes of 2,6-Bis(dialkylphosphinomethyl)pyridines: Improved C–H Activation, Expanded Reaction Scope, and Catalytic Direct Arylation. Organometallics 2017. [DOI: 10.1021/acs.organomet.7b00532] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joseph J. Gair
- Department of Chemistry, University of Chicago, Chicago Illinois 60637, United States
| | - Yehao Qiu
- Department of Chemistry, University of Chicago, Chicago Illinois 60637, United States
| | - Natalie H. Chan
- Department of Chemistry, University of Chicago, Chicago Illinois 60637, United States
| | - Alexander S. Filatov
- Department of Chemistry, University of Chicago, Chicago Illinois 60637, United States
| | - Jared C. Lewis
- Department of Chemistry, University of Chicago, Chicago Illinois 60637, United States
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8
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Liu HE, Triboulet M, Zia A, Vuppalapaty M, Kidess-Sigal E, Coller J, Natu VS, Shokoohi V, Che J, Renier C, Chan NH, Hanft VR, Jeffrey SS, Sollier-Christen E. Workflow optimization of whole genome amplification and targeted panel sequencing for CTC mutation detection. NPJ Genom Med 2017; 2:34. [PMID: 29263843 PMCID: PMC5677973 DOI: 10.1038/s41525-017-0034-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 08/29/2017] [Accepted: 09/11/2017] [Indexed: 12/30/2022] Open
Abstract
Genomic characterization of circulating tumor cells (CTCs) may prove useful as a surrogate for conventional tissue biopsies. This is particularly important as studies have shown different mutational profiles between CTCs and ctDNA in some tumor subtypes. However, isolating rare CTCs from whole blood has significant hurdles. Very limited DNA quantities often can't meet NGS requirements without whole genome amplification (WGA). Moreover, white blood cells (WBC) germline contamination may confound CTC somatic mutation analyses. Thus, a good CTC enrichment platform with an efficient WGA and NGS workflow are needed. Here, Vortex label-free CTC enrichment platform was used to capture CTCs. DNA extraction was optimized, WGA evaluated and targeted NGS tested. We used metastatic colorectal cancer (CRC) as the clinical target, HCT116 as the corresponding cell line, GenomePlex® and REPLI-g as the WGA methods, GeneRead DNAseq Human CRC Panel as the 38 gene panel. The workflow was further validated on metastatic CRC patient samples, assaying both tumor and CTCs. WBCs from the same patients were included to eliminate germline contaminations. The described workflow performed well on samples with sufficient DNA, but showed bias for rare cells with limited DNA input. REPLI-g provided an unbiased amplification on fresh rare cells, enabling an accurate variant calling using the targeted NGS. Somatic variants were detected in patient CTCs and not found in age matched healthy donors. This demonstrates the feasibility of a simple workflow for clinically relevant monitoring of tumor genetics in real time and over the course of a patient's therapy using CTCs.
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Affiliation(s)
| | - Melanie Triboulet
- Department of Surgery, Stanford University School of Medicine, Stanford, CA USA
| | - Amin Zia
- Stanford Center for Genomics and Personalized Medicine, Stanford University, Stanford, CA USA
| | | | - Evelyn Kidess-Sigal
- Department of Surgery, Stanford University School of Medicine, Stanford, CA USA
- Department of Medicine, Division of Hepatology and Gastroenterology, Charité University Hospital, Berlin, Germany
| | - John Coller
- Stanford Functional Genomics Facility, Stanford University, Stanford, CA USA
| | - Vanita S. Natu
- Stanford Functional Genomics Facility, Stanford University, Stanford, CA USA
| | - Vida Shokoohi
- Stanford Functional Genomics Facility, Stanford University, Stanford, CA USA
| | - James Che
- Vortex Biosciences, Inc., Menlo Park, CA USA
| | | | - Natalie H. Chan
- Department of Surgery, Stanford University School of Medicine, Stanford, CA USA
| | - Violet R. Hanft
- Department of Surgery, Stanford University School of Medicine, Stanford, CA USA
| | - Stefanie S. Jeffrey
- Department of Surgery, Stanford University School of Medicine, Stanford, CA USA
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9
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Lowell SY, Kelley RT, Awan SN, Colton RH, Chan NH. Spectral- and Cepstral-Based Acoustic Features of Dysphonic, Strained Voice Quality. Ann Otol Rhinol Laryngol 2017; 121:539-48. [DOI: 10.1177/000348941212100808] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Objectives We sought to determine whether spectral- and cepstral-based acoustic measures were effective in distinguishing dysphonic-strained voice quality from normal voice quality and whether these measures were related to auditory-perceptual ratings of strain severity. Methods Voice samples from 23 speakers with dysphonia characterized predominantly by strained voice quality and 23 speakers with normal voice were acoustically analyzed. Measures related to the prominence of the cepstral peak and the ratio of low- to high-frequency spectral energies, as well as the variation of each, were computed from continuous speech and a sustained vowel. Correlations to perceptually rated strain severity were determined. Results Measures related to the cepstrum were the strongest discriminators between dysphonic-strained voice and normal voice. Variation in the ratio of low- to high-frequency spectral energies also significantly differentiated the two speaker groups. All measures were significantly correlated with perceptually rated strain severity, including an acoustic severity index that incorporated both cepstral- and spectral-based measures. Conclusions Cepstral- and spectral-based measures that have been previously studied in dysphonia characterized by breathiness and roughness are effective in distinguishing strained dysphonia from normal voice quality. The utility of these acoustic measures is supported by their moderate-to-high relationship with perceptually rated strain severity.
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Affiliation(s)
- Soren Y. Lowell
- Department of Communication Sciences and Disorders, Syracuse University, Syracuse, New York
| | - Richard T. Kelley
- Department of Otolaryngology and Communication Sciences, Upstate Medical University, Syracuse, New York
| | - Shaheen N. Awan
- Department of Audiology and Speech Pathology, Bloomsburg University of Pennsylvania, Bloomsburg, Pennsylvania
| | - Raymond H. Colton
- Department of Communication Sciences and Disorders, Syracuse University, Syracuse, New York
| | - Natalie H. Chan
- Department of Communication Sciences and Disorders, Syracuse University, Syracuse, New York
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11
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Yang Z, Mei J, Yang M, Chan NH, Sheng P. Membrane-type acoustic metamaterial with negative dynamic mass. Phys Rev Lett 2008; 101:204301. [PMID: 19113343 DOI: 10.1103/physrevlett.101.204301] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2008] [Revised: 10/07/2008] [Indexed: 05/27/2023]
Abstract
We present the experimental realization and theoretical understanding of a membrane-type acoustic metamaterial with very simple construct, capable of breaking the mass density law of sound attenuation in the 100-1000 Hz regime by a significant margin ( approximately 200 times). Owing to the membrane's weak elastic moduli, there can be low-frequency oscillation patterns even in a small elastic film with fixed boundaries defined by a rigid grid. The vibrational eigenfrequencies can be tuned by placing a small mass at the center of the membrane sample. Near-total reflection is achieved at a frequency between two eigenmodes where the in-plane average of normal displacement is zero. By using finite element simulations, negative dynamic mass is explicitly demonstrated at frequencies around the total reflection frequency. Excellent agreement between theory and experiment is obtained.
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Affiliation(s)
- Z Yang
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
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12
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Chan NH, Genovese CR. A comparison of linear and nonlinear statistical techniques in performance attribution. IEEE Trans Neural Netw 2008; 12:922-8. [PMID: 18249922 DOI: 10.1109/72.935100] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Performance attribution is usually conducted under the linear framework of multifactor models. Although commonly used by practitioners in finance, linear multifactor models are known to be less than satisfactory in many situations. After a brief survey of nonlinear methods, nonlinear statistical techniques are applied to performance attribution of a portfolio constructed from a fixed universe of stocks using factors derived from some commonly used cross sectional linear multifactor models. By rebalancing this portfolio monthly, the cumulative returns for procedures based on standard linear multifactor model and three nonlinear techniques-model selection, additive models, and neural networks-are calculated and compared. It is found that the first two nonlinear techniques, especially in combination, outperform the standard linear model. The results in the neural-network case are inconclusive because of the great variety of possible models. Although these methods are more complicated and may require some tuning, toolboxes are developed and suggestions on calibration are proposed. This paper demonstrates the usefulness of modern nonlinear statistical techniques in performance attribution.
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Affiliation(s)
- N H Chan
- Department of Statistics, Chinese University of Hong Kong Shatin, N.T., Hong Kong
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13
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Chiu LL, Koay ESC, Chan NH, Salto-Tellez M. Sequence confirmation of theEWS-WT1 fusion gene transcript in the peritoneal effusion of a patient with desmoplastic small round cell tumor. Diagn Cytopathol 2003; 29:341-3. [PMID: 14648792 DOI: 10.1002/dc.10397] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Desmoplastic small round cell tumor (DSRCT) is a rare undifferentiated neoplasm. The prognosis is poor, even if therapy is instituted promptly, and thus it is important to differentiate it from other histologically and cytologically similar-looking malignancies of the young adult. We present a case of DSRCT in a 17-yr-old male with disseminated peritoneal disease and peritoneal effusion. The cytology sample showed a malignant small round cell tumor, the classical cytological features of DSRCT, and immunohistochemistry performed in the prepared cell block exhibited an antibody expression profile in keeping with DSRCT. Further material from the effusion was prepared for RNA extraction, following which a reverse-transcriptase polymerase chain reaction (RT-PCR) and sequencing of the t(11;22)(p13;q11 or q12) were carried out. The result showed the presence of the reciprocal translocation and thus confirmed the diagnosis of DSRCT. This case shows how molecular techniques (including sequencing) can be applied to cytology in clarifying and confirming certain difficult diagnosis of undifferentiated neoplasms, DSRCT in this particular case.
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MESH Headings
- Adolescent
- Ascites/diagnosis
- Ascites/genetics
- Ascites/metabolism
- Ascitic Fluid/diagnosis
- Ascitic Fluid/genetics
- Base Sequence
- Biomarkers, Tumor/analysis
- Carcinoma, Small Cell/chemistry
- Carcinoma, Small Cell/genetics
- Carcinoma, Small Cell/pathology
- Humans
- Male
- Molecular Sequence Data
- Oncogene Proteins, Fusion/genetics
- Proto-Oncogene Protein c-fli-1
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Neoplasm/analysis
- RNA-Binding Protein EWS
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Analysis, RNA
- Soft Tissue Neoplasms/chemistry
- Soft Tissue Neoplasms/genetics
- Soft Tissue Neoplasms/pathology
- Transcription Factors/genetics
- Translocation, Genetic
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Affiliation(s)
- L L Chiu
- Molecular Diagnosis Centre, Department of Laboratory Medicine, National University Hospital, Singapore
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14
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Affiliation(s)
- K O Al Saad
- Department of Pathology and Laboratory Medicine, King Fahad National Guard Hospital, Riyadh, Kingdom of Saudi Arabia.
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15
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Yoshida EM, Chan NH, Chan-Yan C, Baird RM. Perforation of the jejunum secondary to AIDS-related gastrointestinal Kaposi's sarcoma. Can J Gastroenterol 1997; 11:38-40. [PMID: 9113797 DOI: 10.1155/1997/425861] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Intestinal perforation in human immunodeficiency virus-positive patients due solely to Kaposi's sarcoma (KS) has rarely been described. A homosexual man with acquired immunodeficiency syndrome-related KS who presented with an acute abdomen is presented. He was found to have a jejunal perforation through a small KS lesion. There were no infectious organisms identified at the site of perforation.
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Affiliation(s)
- E M Yoshida
- Department of Laboratory Medicine and Pathology, St Paul's Hospital, Vancouver, British Columbia
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16
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Yoshida EM, Chan NH, Herrick RA, Amar JN, Sestak PM, Willoughby BC, Whittaker JS. Human immunodeficiency virus infection, the acquired immunodeficiency syndrome, and inflammatory bowel disease. J Clin Gastroenterol 1996; 23:24-8. [PMID: 8835895 DOI: 10.1097/00004836-199607000-00008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The objective of this study was to determine the effect of human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS) on inflammatory bowel disease (IBD). A retrospective survey of the medical records of St. Paul's Hospital and its AIDS-care physicians/gastroenterologists searching for patients with both HIV/AIDS and IBD was conducted. Of 1,839 hospitalized patients (4,459 hospital admissions) from 1989 to 1993, two patients with AIDS/HIV and IBD were found. The physician survey revealed four patients for a total of six patients. Four patients developed de novo IBD--two ulcerative colitis (UC), one Crohn's disease (CrD), and one indeterminate colitis (IC)--after HIV infection. Two patients had UC predating HIV seroconversion. The absolute CD4 count of patients with de novo IBD was 210-700 cells/ml at the time of IBD. The patient with IC maintained quiescent IBD from a CD4 count of 190-30 cells/ml. The other had many relapses before HIV seropositivity. With CD4 count depletion, disease activity improved. IBD medications were discontinued at a CD4 count of 130 cells/ml. Diarrhea returned at a CD4 count of 20 cells/ml; however, sigmoidoscopy was unremarkable, and mucosal biopsy revealed cryptosporidiosis without active UC. No patient had an AIDS-related illness during active IBD. Two patients followed to CD4 counts of < 30 cells/ml suffered AIDS-related infections with quiescent IBD. With a progressive decline in CD4 count, IBD disease activity may improve and remit. The CD4 count at which remission occurs may reflect severe immunodeficiency such that risk for AIDS-related infection is high. Active IBD may occur with lesser degrees of immunodeficiency.
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Affiliation(s)
- E M Yoshida
- Department of Medicine, University of British Columbia, Vancouver, Canada
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Staples CA, Brown MJ, Bai TR, Chan NH. Clinico-radiologic-pathologic conference. Abnormal findings on chest radiographs of an asymptomatic patient. Can Assoc Radiol J 1996; 47:136-9. [PMID: 8612087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- C A Staples
- Department of Radiology, St. Paul's Hospital, Vancouver, BC
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18
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Ellison E, Yuen SY, Lawson L, Chan NH. Fine-needle aspiration diagnosis of extrapulmonary Pneumocystis carinii lymphadenitis in a human immunodeficiency virus positive patient. Diagn Cytopathol 1995; 12:251-3. [PMID: 7621721 DOI: 10.1002/dc.2840120312] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Extrapulmonary Pneumocystitis carinii is an uncommon and probably underdiagnosed complication of pulmonary P. carinii infections. We report the cytologic diagnosis of a case of P. carinii lymphadenitis which presented, without concurrent or historical pneumonitis, in a human immunodeficiency virus (HIV) positive patient who was taking aerosolized pentamidine. The diagnosis was suggested by abundant granular exudate on the cell block. Only scant, fragmented, irregular-shaped granular exudate was present on the direct smears and the Millipore filter preparation. The diagnosis was confirmed by special stains on the cell block.
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Affiliation(s)
- E Ellison
- Department of Pathology and Medicine, St. Paul's Hospital, University of British Columbia, Vancouver, Canada
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19
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Bilbey JH, McLoughlin RF, Kurkjian PS, Wilkins GE, Chan NH, Schmidt N, Singer J. MR imaging of adrenal masses: value of chemical-shift imaging for distinguishing adenomas from other tumors. AJR Am J Roentgenol 1995; 164:637-42. [PMID: 7863885 DOI: 10.2214/ajr.164.3.7863885] [Citation(s) in RCA: 134] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE CT and conventional MR imaging are helpful in characterizing adrenal tumors, but a specific diagnosis is not achieved for a substantial number of lesions. Chemical-shift imaging relies on the different resonance frequencies of protons in water and triglyceride molecules and therefore may permit a more specific diagnosis of adrenal adenomas, which are known to contain abundant lipid. The purpose of this study was to evaluate the usefulness of chemical-shift MR imaging in the differentiation of adrenal adenomas from other adrenal masses. SUBJECTS AND METHODS Forty-one adrenal masses (17 nonhyperfunctioning adenomas, two aldosteronomas, six pheochromocytomas, one ganglioneuroma, five adrenal carcinomas, one lymphoma, seven metastases, one case of extramedullary hematopoiesis, and one leiomyosarcoma) suspected clinically or identified by sonography or CT in 38 patients were prospectively evaluated with MR imaging. Pathologic proof of diagnosis was obtained for 28 lesions, and stability on imaging follow-up (mean, 19 months) was accepted as proof of diagnosis of benign adenoma for 13 lesions. In-phase T1-weighted spin-echo sequences (500/20 [TR/TE]) and opposed-phase gradient-echo sequences (142/6.3, flip angle = 90 degrees) of the adrenal regions were applied. Quantitative analysis of signal intensity loss in the adrenal lesions relative to reference tissues (liver, muscle, and spleen) on in-phase and opposed-phase sequences was done to differentiate adenomas from nonadenomas. Region-of-interest signal intensity measurements were obtained in a standard fashion by selection of the largest possible representative sample. RESULTS Using liver as the reference standard, we found that mean signal intensity ratios were 0.47 (range, 0.23-0.97) for adrenal adenomas and 0.88 (range, 0.65-1.32) for nonadenomas; signal intensity ratios for two adenomas overlapped those of the nonadenomas. Using muscle as the reference standard, we found that mean signal intensity ratios were 0.44 (range, 0.22-0.66) for adrenal adenomas and 0.85 (range, 0.59-1.39) for nonadenomas; signal intensity ratios for two adenomas overlapped those of the nonadenomas. Using spleen as the reference standard, we found that mean signal intensity ratios were 0.45 (range, 0.27-0.73) for adrenal adenomas and 0.97 (range, 0.8-1.18) for nonadenomas, with no overlap. The mean signal intensity ratios were significantly different between adenomas and nonadenomas for all three reference tissues (p < .001). CONCLUSION Our results show that chemical-shift MR imaging is an important new technique that enables the differentiation of adrenal adenomas from other adrenal masses, reducing the need for biopsy and prolonged imaging follow-up in patients with adrenal tumors.
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Affiliation(s)
- J H Bilbey
- Department of Radiology, St. Paul's Hospital, Vancouver, B.C., Canada
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20
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Abstract
PURPOSE To ascertain the usefulness of real-time ultrasound (US)-guided fine-needle aspiration biopsy as an adjunct to clinical, mammographic, and sonographic assessment of solid breast lesions. MATERIALS AND METHODS US-guided fine-needle aspiration biopsy was performed in 225 malignant and 580 benign solid breast lesions confirmed by means of excisional biopsy or with imaging follow-up (mammography or US) performed at approximate intervals of 6, 12, 24, and 36 months. All lesions were classified as palpable or nonpalpable at clinical examination and visible or nonvisible on mammograms. RESULTS In 213 malignant lesions (95%), the cytologic findings were malignant or suspicious, with no false-positive and 12 false-negative cases. Mammography did not enable detection of 58 cancers (26%), 43 of which were palpable. Fifteen cancers discovered with US were nonpalpable and not seen on mammograms. Cytologic diagnosis of fibroadenoma or nonspecific benign cells was correct in 535 lesions. The sensitivity of this method was 95%; specificity, 92%; and overall accuracy, 93%. CONCLUSION Real-time US-guided fine-needle aspiration biopsy is a useful adjunct to clinical, mammographic, and sonographic assessment of solid breast lesions.
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Affiliation(s)
- P B Gordon
- Department of Radiology, University of British Columbia, Vancouver, Canada
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21
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Gerein AN, Brumwell ML, Lawson LM, Chan NH, Montaner JS. Surgical management of pneumothorax in patients with acquired immunodeficiency syndrome. Arch Surg 1991; 126:1272-6; discussion 1276-7. [PMID: 1929829 DOI: 10.1001/archsurg.1991.01410340114016] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Pneumocystis carinii pneumonia in a patient with acquired immunodeficiency syndrome may cause severe alveolar damage, resulting in pneumothoraces that are often bilateral, recurrent, and refractory to accepted methods of treatment. The clinical features, management, and follow-up results were assessed in 22 consecutive patients who presented with a pneumothorax and acquired immunodeficiency syndrome. Seventeen patients died within the time frame of this study. Their average survival time was 147 days. Five surviving patients have lived an average of 366 days. We proposed an algorithm to assist in the management of pneumothoraces in these patients. We concluded that pneumothorax in patients with acquired immunodeficiency syndrome is prognostic of short-term survival. The results in the treatment of pneumothorax in the patient with acquired immunodeficiency syndrome are related to the pathologic lesions of the lung that are associated with Pneumocystis pneumonia and not to the surgical treatment that is employed.
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Affiliation(s)
- A N Gerein
- Department of Surgery, University of British Columbia, Vancouver, Canada
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22
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Bishop WT, Chan NH, MacDonald IL, Tutassaura H. Malignant primary cardiac tumour presenting as superior vena cava obstruction syndrome. Can J Cardiol 1990; 6:259-61. [PMID: 2224613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A 71-year-old male with a malignant primary cardiac lymphoma nearly filling the right atrium presented with symptoms of obstruction of the tricuspid valve and inflow to the right atrium. The tumour was resected as fully as possible; however, a portion of the tumour that had invaded the inferior aspect of the right atrium and the atrioventricular groove could not be excised. Eighteen months after initial presentation, the patient is well and the tumour has not recurred. This is the first case of symptom-free survival of primary cardiac lymphoma for as long as 18 months.
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Affiliation(s)
- W T Bishop
- Prince George Regional Hospital, British Columbia
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Abstract
One hundred eighty-two fine needle aspirations (FNAs) of head and neck masses performed between the years 1981 and 1987 were studied retrospectively. Seventeen FNAs were unsatisfactory. Of the remaining 165, 148 (90%) were followed up with either surgery or clinical follow-up of at least 12 months' duration. Seventy-one of these aspirates were malignant. Fifty-six cases of metastatic carcinoma and 13 cases of lymphoma were diagnosed. The positive predictive value for metastatic carcinoma and lymphoma was 100%, and the sensitivities were 92% and 100%, respectively. For benign salivary gland lesions, the positive predictive value was 94%, whereas for malignant lesions it was 100%. One case of carcinoma ex-pleomorphic adenoma was missed by FNA. No complications were associated with FNA. We conclude that FNA is a safe and accurate technique, well suited to the in-office evaluation of neck masses of differing causes.
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Affiliation(s)
- R Schwarz
- Department of Surgery, St. Paul's Hospital, Vancouver, British Columbia, Canada
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Ajzen SA, Goldenberg SL, Allen GJ, Cooperberg PL, Chan NH, Jones EC. Palpable prostatic nodules: comparison of US and digital guidance for fine-needle aspiration biopsy. Radiology 1989; 171:521-3. [PMID: 2649927 DOI: 10.1148/radiology.171.2.2649927] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This study was undertaken to evaluate the use of transrectal sonographically guided fine-needle aspiration biopsy and to compare sonographic with digital guidance for biopsy. In 62 patients in whom prostatic carcinoma was suspected at digital rectal examination, fine-needle aspiration biopsies were performed transperineally under sonographic guidance and transrectally under digital guidance. These patients had 89 nodules, 73 of which were sampled with both techniques. Malignant cells were obtained under digital guidance in 17 of 73 nodules (23%) and under sonographic guidance in 16 (22%). An additional seven nodules, which were not seen sonographically, were sampled under digital guidance and proved to be negative. In nine other nodules that were nonpalpable and evident only with sonography, malignant cells were obtained under sonographic guidance in three. These findings indicate that sonographic guidance for fine-needle aspiration biopsy is as good as digital guidance for palpable lesions.
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Affiliation(s)
- S A Ajzen
- Department of Radiology, St Paul's Hospital, University of British Columbia, Vancouver, Canada
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25
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Abstract
We present our results of 3 biopsy techniques applied to each of 62 patients with clinically suspicious prostatic nodules. Transrectal digitally guided and sonographically guided transperineal fine needle aspiration biopsies were followed by digitally guided transperineal core biopsy in all cases. Adenocarcinoma was confirmed in 25 patients by 1 or more of these techniques. Our results indicated that 7 of 25 cancer cases (28 per cent) were detected by only 1 of 3 applied methods of biopsy and 56 per cent were detected by all 3 techniques. When a clinical suspicion of malignancy remains after a negative aspiration or core biopsy consideration should be given to alternative forms of biopsy to establish a diagnosis.
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Affiliation(s)
- S L Goldenberg
- Department of Surgery (Urology), St. Paul's Hospital, University of British Columbia, Vancouver, Canada
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26
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Abstract
Herein is reported the cytologic features of four cases of cystic neoplasms of the pancreas as seen in fine-needle aspirates. Cytologically, the cases fall into two distinct groups: mucinous cystic neoplasm and serous cystadenoma. The aspirates from the mucinous cystic neoplasms characteristically showed columnar mucus-secreting epithelial cells, some of which were arranged in a papilloglandular pattern, with abundant mucous material in the background. The aspirates from the serous cystadenoma yielded small sheets of cuboidal cells with small nuclei and clear cytoplasm, without a background of mucous material. This cytologic division corresponds closely to the histologic classification proposed by Compagno and Oertel and hence is of prognostic and therapeutic value. The diagnostic challenges confronted by the cytopathologist are (1) to differentiate neoplastic cysts from the inflammatory pseudocysts; (2) to differentiate neoplastic epithelium from the normal epithelium of the bowel and pancreatic ducts; and (3) to differentiate mucinous cystic neoplasms from serous cystadenomas.
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Affiliation(s)
- E C Jones
- Department of Pathology, Vancouver General Hospital, B.C., Canada
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Suen KC, Magee JF, Halparin LS, Chan NH, Greene CA. Fine needle aspiration cytology of fibrolamellar hepatocellular carcinoma. Acta Cytol 1985; 29:867-72. [PMID: 2996274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The major cytologic features seen in fine needle aspirates from two cases of fibrolamellar hepatocellular carcinoma were: liver-like tumor cells, characterized by plump, polygonal forms with eosinophilic, granular cytoplasm; large oval nuclei with extremely prominent solitary nucleoli; and parallel bands of fibrous tissue and fibrocytes seen within the tumor fragments. Other helpful features included intracytoplasmic hyaline globules and well-delineated pale bodies. Clinically, the tumors occurred in young patients with noncirrhotic livers and ran a more favorable course than do other types of hepatocellular carcinoma.
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Chan NH, Boyko WJ, Schellenberg RR, Copland GM, Hogg JC. A case of eosinophilic pneumonia. Unusual immune complex vasculitis in the skin. Chest 1982; 82:113-5. [PMID: 7083918 DOI: 10.1378/chest.82.1.113] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
This report concerns a 28-year-old woman with biopsy-proved eosinophilic pneumonia and cutaneous vasculitis. The skin biopsy specimen contained prominent granular deposits of IgM and C3 in dermal vessels, and elevated circulating immune complexes were detected. The association of cutaneous immune complex vasculitis with circulating immune complexes in chronic eosinophilic pneumonia is unusual and to our knowledge has not been previously reported. While the pathogenesis of chronic eosinophilic pneumonia is unknown, circulating immune complexes may represent a mechanism in the development of tissue eosinophilia.
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Chan NH, Chaloupka J. Regulation of the formation of proteinases in Bacillus megaterium. VI. Some physicochemical properties of the proteinases from sporogenic and asporogenic Bacillus megaterium KM. Folia Microbiol (Praha) 1972; 17:347-52. [PMID: 4627856 DOI: 10.1007/bf02884101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Chan NH, Chaloupka J. Regulation of the formation of proteinases in Bacillus megaterium. V. Characterization of two megaterioproteinases differing in the control of their synthesis. Folia Microbiol (Praha) 1972; 17:281-90. [PMID: 4627015 DOI: 10.1007/bf02880203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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